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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
Which of the following ion is spectator ion in the reaction given below: `Zn+2H^(+)+2Cl^(-)rarrZn^(2+)+2Cl^(-)+H_(2)` |
| Answer» `X^(-)` ion is `Br^(-)` or `I^(-)` ion. | |
| 502. |
Why does `NH_(3)` acts as a Lewise base? |
| Answer» Nitrogen atom in `NH_(3)` has one lone pair of electron which is available for donation, hence lewis base. | |
| 503. |
Write redox reactions between fluorine and water. |
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Answer» (i) `F_(2)` reacts with water to give `O_(2) " and " O_(3)` `2Fe_(2)+2H_(2)O to 4HF +O_(2)` `3Fe_(2)+2H_(2)O to 6 HF+O_(3)`. (ii) `Cl_(2)` reacts with water in the presence of sunlight to evolve `O_(2)`. `2Cl_(2)+2H_(2)O overset("Sunlight") to 4HCl+O_(2)` |
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| 504. |
Which of the following compound react with `BF_(3)`?A. EthersB. `H_(2)O`C. EthylalcoholD. `NH_(3)` |
| Answer» Correct Answer - A::B::C::D | |
| 505. |
Which of the following compounds contain boron?A. BoraxB. ColemariteC. FeldsparD. kernite |
| Answer» Correct Answer - A::B::D | |
| 506. |
On reaction of moist `SO_(2)` with potassium permangnate (Acidic) which is correctly observed?A. Colour of `KMnO_(4)` is decolourisedB. `SO_(2)` is oxidised to `SO_(3)`C. `MnO_(4)^(-)` is reduced to `MnO_(2)`D. All of these |
| Answer» Correct Answer - A | |
| 507. |
Noble gases do not react with other elements becauseA. the size of their atom is very smallB. they are found in abundanceC. there electrons are completlely parired up and they have completely filled electron subshellsD. they are monoatomic |
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Answer» Correct Answer - 3 All the subshells are completely filled and all the electrons are paired leading to very high `Delta_(i)H_(l)` and positive `Delta_(eg)H`. |
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| 508. |
Which of the following is isoelectronic pair ?A. `Icl_(2), ClO_(2)`B. `BrO_(2)^(-), BrF_(2)^(+)`C. `ClO_(2), BrF`D. `CN^(-), O_(3)` |
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Answer» Correct Answer - B `BrO_(2)^(-) " and " BrF_(2)^(+)` ions are isoelectronic in nature. Both have (35+17)=52 electrons. |
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| 509. |
If chlorine gas is passed through hot NaOH solution, two changes are observed in the oxidation number of chlorine during the reaction. These are ____ and ___A. 0 to `+5`B. 0 to `+3`C. 0 to `-1`D. 0 to `+1` |
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Answer» Correct Answer - A::C Both are correct answers. `3overset(0)(Cl_(2))+6NaOH to 5Naoverset(-1)(Cl)+Naoverset(+5)(ClO_(3))+3H_(2)O` |
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| 510. |
Why tetrahalides other than carbon can increase its co-ordination number? |
| Answer» Due to availability of vacant d-orbital. | |
| 511. |
The member of group 14 form tetrahalides of the type `MX_(4)`. Which of the following halides connot be readily hydrolysed by water?A. `CX_(4)`B. `SiX_(4)`C. `GeX_(4)`D. `SnX_(4)` |
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Answer» Correct Answer - A Except carbon halides, other halides are readily hydrolysed by water. In `CCI_(4)`, the central atom cannot accommodate lone pair of electrons from oxygen atom of water molecule due to absence of d-orbitals |
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| 512. |
Identify the compounds A,X and Z in the following reactions `A+2HCl+5H_(2)Orarr2NaCl+X` `Xoverset(Delta)underset(370K)(rarr)HBO_(2) overset(Delta)underset(gt370K)(rarr)Z` |
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Answer» (i) `underset("Borax (A)")(Na_(2)B_(4)O_(7))+2HCl+5H_(2)Orarr2NaCl+underset("Orthoboric acid (X)")(4H_(3)BO_(3))` (ii) `H_(3)BO_(3)overset(Delta,370K)(rarr) underset("Metaboric acid")(HBO_(2))+H_(2)O` (iii) `4HBO_(2) underset(-H_(2)O)overset(Delta gt370K)(rarr)underset("Tetraboric acid")([H_(2)B_(4)O_(7)])underset("Heat")overset("Red")(rarr)underset("Boron trioxide (Z)")(2B_(2)O_(3)+H_(2)O)` |
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| 513. |
Identify X in reaction `: X + underset("steam")(2 H_(2)O) overset(Delta)(to) XO_(2) + 2H_(2)`A. CB. SiC. GeD. Sn |
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Answer» Correct Answer - D `Sb + underset("Steam")(2H_(2) O) to SnO_(2) + 2h_(2)` Tin decomposes steam to form tin dioxide and hydrogen gas. |
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| 514. |
Draw the shapes of the following molecules : (i) `XeOF_(4) (ii) H_(2)SO_(4)` |
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Answer» (i) For the shape of `XeOF_(4)` , (ii) For the shape of `H_(2)SO_(4)`, |
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| 515. |
Draw the structure of the following molecules (i) `H_(3)PO_(2) (ii) H_(2)S_(2)O_(7) (iii) XeOF_(4)`. |
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Answer» (i) `H_(3)PO_(2)`, (ii) `H_(2)S_(2)O_(7)` , (iii) `XeOF_(4)`, |
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| 516. |
`IO_(3)^(-)+I^(-)+H^(+) to` |
| Answer» `IO_(3)^(-)+5I^(-)+6H^(+) to 3I_(2)+3H_(2)O` | |
| 517. |
`I_(2)+S_(2)O_(3)^(2-) to` |
| Answer» `I_(2)+underset("Thiosulphate ion")(2S_(2)O_(3)^(2-)) to underset("Tetrathionate ion")(S_(4)O_(6)^(2-))+2I^(-)` | |
| 518. |
`BrO_(3)^(-)+F_(2)+2OH^(-) to ` |
| Answer» `BrO_(3)^(-)+F_(2)+2OH^(-) to BrO_(4)^(-)+2F^(-)+H_(2)O` | |
| 519. |
`XeF_(2)+H_(2)O to` |
| Answer» `2XeF_(2)+2H_(2)O to 2Xe+4HF+O_(2)` | |
| 520. |
`XeF_(6)+PF_(5) to ` |
| Answer» `XeF_(6)+PF_(5) to [XeF_(5)]^(+)[PF_(6)]^(-)` | |
| 521. |
The hybridisation of nitrogen in `R_(2)NH` is :A. `sp^(3)`B. `sp^(2)`C. spD. `dsp^(2)` |
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Answer» Correct Answer - A Amines are derivatives of ammonia. N atom is `sp^(3)` hybridised |
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| 522. |
How are `XeO_3` and `XeOF_4` prepared? |
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Answer» (i) `XeO_(3)` can be prepared in two ways as shown. `6XeF_(4) + 12 H_(2) O to 4 Xe + 2 XeO_(3) + 24 HF + 3O_(2)` `X eF_(6) + 3H_(2)O to XeO_(3) + 6 HF` (ii) `XeOF_(4)` can be prepared using `XeF_(6)`. `XeF_(6) +H_(2)O to XeOF_(4) + 2HF` |
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| 523. |
Oxygen molecule has the formula `O_(2)` while sulphur is `S_(8)`. Why ? |
| Answer» In the molecule of oxygen, the two oxygen atoms are linked to each other by double bond (O=O) i.e., one sigma bond formed by axial overlap and one pi-bond formed as a result of sidewise overlap. Therefore, oxygen exists as a diatomic molecule. Multiple bonding is not possible in sulphur due to its large atomic size. The sidewise overlap is not effective. Each sulphur atom is linked to two sulphur atoms on either sides resulting in `S_(8)` molecule with puckered ring structure. | |
| 524. |
Why is `H_(2)S` less acidic than `H_(2)Te` ? |
| Answer» `H_(2)S` is less acidic `(K_(a)=1.0xx10^(-7)) " than" H_(2)Te (2.3xx10^(-7))` because the cleavage of H-Te bond is easier than that of H-S bond due to its more bond length. Therefore, release of `H^(+)` from `H_(2)Te` takes place more readily than from `H_(2)S` molecule. | |
| 525. |
The oxidation state of nitrogen is highest inA. `N_(3)H`B. `NH_(3)`C. `NH_(2)OH`D. `N_(2)H_(4)` |
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Answer» Correct Answer - A O.S. of N in `N_(3)H=(-1)/(3)` O.S. of N in `NH_(3)=-3` O.S. of N in `NH_(2)OH=-1` O.S. of N in `N_(2)H_(4)=-2` |
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| 526. |
Oxygen will directly react with each of the following elements exceptA. `S`B. `P`C. `Cl`D. `Na` |
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Answer» Correct Answer - 3 Since the oxides of chlorine are strongly endothermic compounds and have positives free energies of formation dioxygen does not react directly with dichlorine. Others do reacts `S(s)+O_(2)(g) overset(Delta)(rarr) SO_(2)(g)` `P_(4)(s)+5O_(2)(g) overset(Delta)(rarr) P_(4)O_(10) (s)` `4Na(s)+O_(2)(g) overset(Delta)(rarr) 2Na_(2)O(s)` |
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| 527. |
Which one of the following is hardest compound of boron ?A. `B_(2)O_(3)`B. BNC. `B_(4)C`D. `B_(2)H_(6)` |
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Answer» Correct Answer - C Boron carbide `B_(4)C` is a very hard substance like SiC. |
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| 528. |
`NaBH_(4) + I_(2) to X + Y + X` `BF_(3) + NaH overset(450K)(to) X + P` `BF_(3) + LiAIH_(4) to X + Q + R` X,Y,Z,P,Q and R reaction are `{:(X,Y,Z,P,Q,R):}`A. `{:(Na_(4)B_(4)O_(7),NaI,HI,HF,LiF,AIF_(3)):}`B. `{:(B_(2)H_(6),NaI,H_(2),NaF,LiF,AIF_(2)):}`C. `{:(B_(2)H_(6),BH_(3),NaI,B_(3)N_(3)H_(6),AI_(2)F_(6),AIF_(3)):}`D. `BH_(3),B_(2)H_(6),H_(2),B_(3)N_(3)H_(6),LiF,AIF_(3)` |
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Answer» Correct Answer - B `2NaBH_(4) + I_(2) to underset((X))(B_(2)H_(6)) + underset((Y))(2NaI) + underset((Z))(H_(2))` `2BF_(3) + 6NaH overset(450 k)(to) underset((X))(B_(2)H_(6)) + underset((F))(6NaF)` `4BF_(3) + 3LiAIH_(4) to underset((x))(2B_(2)H_(6)) + underset((Q))(3LiF) + underset((R ))(3AIF_(3))` |
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| 529. |
Why does `AlCl_(3)` fumes in air?A. It is hygroscopic in nature.B. It gives out chlorine when exposed to air.C. It is hydrolysed in moist air giving fumes of HCID. It loses water when exposed to moist air. |
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Answer» Correct Answer - C Anhydrous `AICI_(3)` is hydrolysed in moist air and fumes of HCI are given out. |
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| 530. |
Which of the following properties correctly explain `SiO_(2)`?A. Linear, basicB. Tetrahedral, acidicC. Tetrahedral, basicD. Linear, acidic |
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Answer» Correct Answer - B `SiO_(2)` is slightly acidic in nature. In `SiO_(2)`, Si has tetrahedral arrangement. |
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| 531. |
Why is ICl more reactive than `I_(2)` ? |
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Answer» When molten Icl is electrolysed, `I^(+)` ion is formed at cathode which gets reduced to `I_(2)` `underset(("Molten"))(2ICl) harr underset(("Cathode"))I^(+)+underset(("Anode"))[Icl_(2)]^(-) , 2I^(+)+2e^(-) to I_(2)` |
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| 532. |
Which of the following cannot undergo Lewis acid-base reaction with `BF_(3)`?A. `F^(-)`B. `NH_(3)`C. `AlCl_(3)`D. `(C_(2)H_(5))_(2)O` |
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Answer» Correct Answer - C Like `BF_(3)`, the compound `AlCl_(3)` is also electron deficient. |
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| 533. |
Which of the following is a liquid?A. `BI_(3)`B. `BF_(3)`C. `BCl_(3)`D. `BBr_(3)` |
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Answer» Correct Answer - D `BF_(3)` and `BCl_(3)` are gases, `BBr_(3)` is a liquid, while `BI_(3)` is a solid. The volatility of the halides decreases with increasing relative molecular mass. |
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| 534. |
The compound (s) which generate (s) `N_(2)` upon thermal decomposation is (are) :A. `NH_(4)NO_(3)`B. `(NH_(4))_(2)CO_(7)`C. `Ba(N_(3))_(2)`D. `Mg_(2)N_(2)` |
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Answer» Correct Answer - B::C Both `(NH_(4))_(2)Cr_(2)O_(7) " and " Ba(N_(3))_(2)` decompose below `300^(@)C`. `NH_(4)_(2)Cr_(2)O_(7) overset("heat")to N_(2)+Cr_(2)O_(3)+H_(2)O` `Ba(N_(3))_(2) overset("heat")to Ba+3N_(2)` Both `NH_(4)NO_(3)` and `Mg(NO_(3))_(2)` donot decompose below `300^(@)C`. They decompose at higher tempertures. |
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| 535. |
Assertion Nitrogen has higher first ionisation energy than oxygen. Reason Atomic radius of nitrogen is smaller than that of oxygen.A. If both assertion and reason are correct and reason is correct explanation for assertion.B. If both assertion and reason are correct but reason is not correct explanation for assertion.C. If assertion is correct but reason is incorrect.D. If both assertion and reason are incorrect. |
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Answer» Correct Answer - C Correct reason : The configuration of N atom is more symmetrical than that of oxygen |
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| 536. |
Based on the compounds of group 15 elements, the correct statement (s) is (are)A. `Bi_(2)O_(5)` is more basic than `N_(2)O_(5)`B. `NF_(3)` is more covalent than `BiF_(3)`C. `PH_(3)` boils at a lower temperture than `NH_(3)`D. The N - N single bond is stronger than P - P single bond. |
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Answer» Correct Answer - A::B::C All these statements are correct. The ` overset(* *)N-N` bond angle is weaker due to greater repulsive interactions in the non-bonded or lone pairs of electrons on the two N atoms. |
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| 537. |
About `"______"` by mass of the atmosphere consists of dioxygenA. `23%`B. `21%`C. `20%`D. `25%` |
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Answer» Correct Answer - 1 Oxygen exists in the free form as `O_(2)` molecules and make up `20.9%` by volume and `23%` by mass of the atmosphere .The proportion remains constant because the dioxygen consumed during respiration and combustion is continually replaced as a result of photosynthesis. |
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| 538. |
Which of the following is called Epsom salt?A. `BaSO_(4)`B. `CaSO_(4).2H_(2)O`C. `MgSO_(4).7H_(2)O`D. `Na_(2)SO_(4)` |
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Answer» Correct Answer - 3 Epsom salt, `MgSO_(4),7H_(2)O` ,is a white crystalline soluble salt ,used in medicine and in leather processing In the combined state sulpher occurs as sulphide ores and as sulphates.Coal and crude petrolemium contain small percentage of sulpher compounds and so ,sometimes ,does natural gas. Sulpher in the native form can be obtained from volcanic sources in many places,but these sources and little used now except in japan and Mexico .From Biblical times up till the `20^(th)` centuary volcane sources provided the major sources of S. In early times S in the form of brimstone (burning rock) was used for fumigation. From the `13^(th)` centuary until middle of the `19^(th)` centuary it was used to make gun the power. In th epresent century the major use has been to make `H_(2)SO_(4)` |
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| 539. |
The mixture covalence of oxygen isA. twoB. fourC. ThreeD. six |
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Answer» Correct Answer - 2 In practice ,`O` is never more than divalent because when it has formed two covalent bonds it has attained a noble gas configuration ,and there are no low energy empty orbitals (such as d-orbitals )which can be used to form further bonds.Using its two lone pairs it can extend its covalence to four. However, the rest of the Group `16` element have empty d orbitals in their valence shell which can be used for bonding and hence they can form four or six bonds by unpiring ns and np electrons. The `+4` show sboth oxidizing and reducting properties.Fluorine and oxygen bring out the maximum oxidation state of `+6`.Compounds in the `+6`state show oxidizing properties.The higher oxidation state becomes less stable on descending the group.These compounds are typically volatile because they are covalents. |
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| 540. |
The chemistry of polonium is not well known becauseA. it is difficult to extractB. it is very scarceC. it is highly reactiveD. it iis radioactive |
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Answer» Correct Answer - 4 All isotopes of polonium (discovered by Marie Curie by processing very large amounts of thorium and uranium minerals and separating the decay products)are highly radioactive.The most stable isotope is `._(84)^(120)(Po)`, but this ab intense `alpha` emitter and has a half lige of `138`days. The `alpha` emission decomposes water, which complicates any studies of `Po` compounds in aqueous solutions.Thus,the chemistry of `Po` is not known. Polonium is one of the decay products `._(82)^(210)Pbunderset(f_(1//2=22.3y))overset(beta)rarr ._(83)^(210)Biunderset(f_1//2=5.0d)overset(beta)rarr ._(84)^(210)Pounderset(t_1//2=5.0d)overset(alpha)rarr ._(82)^(206)Pb` Polonium is now made arifically in gram qunatities from bismuth by neutron irradiation in a nuclear reactor. The metal is extracted by submission: `._(83)^(209)Bi+_(0)^(1)n rarr_(83)^(210)Bi rarr_(84)^(210)Po +_(-1)^(0)e` |
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| 541. |
Group 16 element (except polonium ) are called chalcogens becauseA. a large number of acids contain these elements paticularly oxygen and sulphurB. these element of particularly `O` and `S` are present in many metallic ores mainly as oxide and sulphidesC. all these elements exhibits allotropyD. these element mainly form anions. |
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Answer» Correct Answer - 2 Because a large number of metal ores are either oxides or sulphides.The name chalcogens is derived from the Greek word for brass and points to the association of sulphur and its congeners with copper.Most copper minerals contains either oxygen or sulphur and frequently the other members of the group. |
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| 542. |
How is `O_(3)` estimated quantitatively ? |
| Answer» On reaction with excess Kl buffered with borate `l_(2)` liberated which is titrated against standard `Na_(2)S_(2)O_(3)`. | |
| 543. |
Which of the following oxoacids of phosphorus contains a `P-P` bond?A. Hypophosphoric acidB. Pyrophosporic acidC. Pyrophosphorous acidD. Polymetaphosporic acid |
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Answer» Correct Answer - 1 Hyprosphoric acid is the only oxacid of phosphorus which conrtains a `P-P` bond: `HO-underset(OH)underset(|)overset(O)overset(||)(P)-underset(OH)underset(|)overset(O)overset(||)(P)-OH` `underset(("Pyrophosphric"),("acid"))(HO-underset(OH)underset(|)overset(O)overset(||)(P)-O-underset(OH)underset(|)overset(O)overset(||)(P)-OH)" "underset(("Pyrophosphorous"),("acid"))(HO-underset(H)underset(|)overset(O)overset(||)(P)-O-underset(H)underset(|)overset(O)overset(||)(P)-OH)` Pyrophosphorous acid is obtained by reacting `PCl_(3)` with phosphorous acid |
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| 544. |
Phosphates can be estimated quantitatively by precipitating them asA. `Ca_(3)(PO_(4))_(2)`B. `AlPO_(4)`C. `Mg_(3)(PO_(4))_(2)`D. `MgNH_(4)PO_(4)` |
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Answer» Correct Answer - 4 Phosphates precipate magnesium ammonium phosphate when added to an ammoniacal solution of magnesium chloride .If this precipitate is washed, filtered and ignited it forms magnesium diphoshate .This can weighted and thus phosphates can be estimated qantitatively. `2Mg^(2+)(NH_(4)^(+))PO_(4)^(3)(s)rarr(Mg^(2+))_(2)P_(2)O_(7)^(4-)(s)+2NH_(3)(g)+H_(2)O(l)` |
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| 545. |
All phosphates give a bright yellow precipitate of `"_____"` when dissolved in nitric acid and warmed ( not boiled ) with an excess of ammonium molylbdate solutionA. `(NH_(4))_(3)PO_(4).12MoO_(3)`B. `(NH_(4))_(3)PO_(4).11MoO_(3)`C. `(NH_(4))_(3)PO_(4).10MoO_(3)`D. `(NH_(4))_(3)PO_(4).14MoO_(3)` |
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Answer» Correct Answer - 1 Phosphorous (including orthophosporous acid)give a yellow precipitate of ammonium phosphomolybdate when warned to about `60^(@)C` with nitric acid and ammonium amolybdate solution: `H_(3)PO_(4)+21HNO_(3)+12(NH_(3))_(2)MoO_(4)rarr(NH_(4))_(3)PO_(4)12MoO_(3)+21NH_(4)NO_(3)+12H_(2)O` This same test is also given by condensed phosphates ,since hydrolysis to normal phosphates takes place on warning ,However ,precipitaion of ammonium phosphomolybdate in these cases is a much slower process. Arsenates give a similar percipitate only when boiled with these reagents. |
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| 546. |
Borax is used for……..resistant glazed coating to earthen-wares.A. heatB. scratchC. stainD. all of these |
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Answer» Correct Answer - D Borax is heat, scratch, and stain resistant. |
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| 547. |
Which of the following gives correct arrangement of compounds involved based on their bond strength?A. `HF gt HCl gt HBr gt HI`B. `HI gt HBr gt HCl gt HF`C. `HCl gt HF gt HBr gt HI`D. `HF gt HBr gt HCl gt HI` |
| Answer» Correct Answer - A | |
| 548. |
The element of group 17 whose half life is in milliseconds only isA. TsB. TeC. AtD. Og |
| Answer» Correct Answer - A | |
| 549. |
The comparatively high b.pt. of HF is due toA. high reactivity of fluorineB. small size of hydrogen atomC. formation of hydrogen bondsD. small size of fluorine. |
| Answer» Correct Answer - C | |
| 550. |
Fill in the blanks. The high reactivity of fluorine is due to its ____ dissociation energy. Its shows _____ only oxidation state. It has ____ electron affinity than chlorine. Among all hydrogen halides boiling point is highest for_____.A. low, -1, lower, HFB. high,+ 1, higher, HFC. low, +1, lower, HClD. high, -1, higher, HF |
| Answer» Correct Answer - A | |